Substituted dichlorosulfenamides

ABSTRACT

Substituted dichlorosulfenamides are prepared from dichloromethyl sulfenyl chlorides by reaction with a primary or secondary amine. The substituted dichlorosulfenamides are pesticidally active and particularly useful as pre-emergent herbicides.

United States Patent 11 1 1111 3,888,925 Phillips June 10, 1975 1SUBSTITUTED DICHLOROSULFENAMIDES FOREIGN PATENTS OR APPLICATIONSlnventorl Wendell y Phillips, Olivette, 789,273 1/1958 United Kingdom260/551 s [73] Assignee: Monsanto Company, St. Louis, Mo.

OTHER PUBLICATIONS [22] Filed: Apr. 30, 1973N-(Polyhaloalkanesulfenyl)sulfenamides," Sasse et [21] 355,836 a1.,Chem. Abstracts 63, 98756 (1965).

Related US. Application Data [62] Division of Ser. No. 159,034, July 1,1971, Pat. No. Primary Examiner R v Hines As'sistqnt ExaminerThomas A.Waltz t R' 521 US. Cl. 260/551 s; 71/94; 71/95; A mmey Agent chard Hshear 71/98; 71/103; 260/239 A; 260/239 B; 260/293.71; 260/326.3;260/326.5 S; 260/326.62; 260/456 A; 260/465.5 R; [57] ABSTRACT 260/470;260/481 R; 260/561 A; 260/561 S; Substituted dichlorosulfenamides areprepared from 260/562 N dichloromethyl sulfenyl chlorides by reactionwith a [51] hit. Cl. C07C 145/00 primary or Secondary amine. Thesubstituted [58] Fleld of Search 260/551 S chlorosulfenamides arepesticidany active and particu larly useful as pre-emergent herbicides.[56] References Cited UNITED STATES PATENTS 6 Claims, N0 Drawings2,553,775 5/1951 Hawley et a1. 260/551 S SUBSTITUTEDDICHLOROSULFENAMIDES This is a division, of application Ser. No.159,034, filed July 1, 1971, now U.S. Pat. No. 3,766,172.

This invention relates to substituted dichlorosulfenamides of theformula and their manufacture from the corresponding dichloromethylsulfenyl chlorides of the formula and an amine of the formula wherein Eis C E N,

X is phenyl, halophenyl or lower alkyl phenyl, Y is lower alkyl orbenzyl, R is lower alkyl, lower alkoxyalkyl, or lower alkoxy, R isphenyl, halophenyl, lower alkyl phenyl, lower alkyl, lower alkoxyalkyl,or lower alkoxy or R and R when taken together are alkylene of theempirical formula c l-l wherein n is an integer from 4 through 8,inclusive, and having from 4 through 8 carbons in a continuous chainbetween the nitrogen terminal valence bonds, A is hydrogen, methyl loweralkenyl, methyl lower alkynyl, lower alkyl, lower alkoxyalkyl, or loweralkoxy and B is methyl lower alkenyl, methyl lower alkynyl, phenyl,halophenyl, lower alkyl phenyl, lower alkyl, lower alkoxyalkyl, or loweralkoxy or A and B when taken together are alkylene of the empiricalformula C ll wherein n is an integer from 4 through 8, inclusive, andhaving from 4 through 8 carbons in a continuous chain between thenitrogen terminal valence bonds.

Lower alkyl is alkyl having from 1 to 5 carbons. Examples of lower alkylinclude, but are not limited to, methyl, ethyl, propyl, isopropyl,butyl, sec-butyl, isobutyl, tert-butyl, and pentyl.

Lower alkoxy have from 1 to 5 carbons. Examples of alkoxy include, butare not limited to, methoxy, ethoxy, propoxy, butoxy and pentoxy. Loweralkoxyalkyl have from 2 to 8 carbons. Examples of lower alkoxyalkyl arepropoxymethyl, butoxybutyl, butoxyethyl, methoxymethyl, andethoxypropyl.

Halo is a halogen selected from the group consisting of fluorine,chlorine, bromine and iodine.

Lower alkenyl and lower alkynyl have from 2 through 4 carbons. Examplesof lower alkenyl include, but are not limited to vinyl, allyl andcrotyl. Examples of lower alkynyl include, but are not limited to,acetenyl, 2-propynyl (propargyl), l-methyl-Z-propynyl, 2- butynyl, and3-butynyl. In compounds of this invention lower alkenyl and loweralkynyl are attached to the nitrogen of the amine by a methylene groupso that the carbon adjacent to the nitrogen is always saturated.

Exemplary of halophenyl and lower alkyl phenyl are substituted phenylsof the formula wherein Z is halo, trihalomethyl, or lower alkyl and m isan integer from 1 through 3, inclusive.

Examples of alkylene of the empirical formula C H wherein n is aninteger from 4 through 8, inclusive, and having from 4 through 8 carbonsin a continuous chain between the nitrogen terminal valence bondsinclude but are not limited to pyrrolidinyl, piperidinyl,hexamethyleneimino, heptamethyleneimino, octamethyleneimino,2-ethylpyrrolidinyl, 3-butylpyrrolidinyl, 2,S-dimethylpyrrolidinyl,2,5-diethylpyrrolidinyl, 3,4-dimethylpyrrolidinyl, 2-pipecolinyl,3-pipecolinyl, 4-pipecolinyl, 2,6-dimethylpiperidinyl, 2-ethyl-6-methylpiperidinyl, 2-propylpiperidinyl, 3- methylhexamethyleneimino,3,4-dimethylhexamethyleneimino, and the various isomeric forms thereof.

The compounds of this invention are conveniently and efficientlyprepared by the reaction of about 1 molecular proportion of adichloromethyl sulfenyl chloride of the formula ECCl SCl and 2 molecularproportions of an amine of the formula wherein E, A and B have theaforementioned significance. The reaction is postulated to proceed asfollows:

A QECCI SN One of the molecular proportions of the amine is consumed bysalt formation with the liberated hydrochloride. Where the amine is ofhigh value, difficult to obtain, or for any reason it is desired tominimize the amount of amine used, it may be preferred to conduct thereaction in the presence of another l-lCl scavenger.

In this embodiment it is postulated that the reaction proceeds asfollows:

A scavenger A The reaction mass may consist only of the aforedescribedreactants and their reaction products or it may contain other componentsin addition such as diluents, other inert materials and solvents, i.e.,common organic liquids which are inert under the reaction conditions andwhich may dissolve one or more of the reactants or products of thereaction, which solvents are exemplified by but not limited to aliphatichydrocarbons, such as pentane, hexane, mineral spirits, etc., aromaticssuch as benzene, toluene, xylenes, etc., ethers such as diethyl ether,diisopropyl ether, petroleum ether, etc., esters such as methyl acetate,ethyl acetate, propyl acetate, etc., and other organics such astetrahydrofurane, etc. The hydrochloride salt by-product is generallynot soluble in the above solvents. Accordingly, the insoluble saltusually forms a precipitate in the reaction mass and may be easilyremoved by filtration. When filtration is not desired or the salt issoluble in the solvent, the salt may be readily removed from thereaction mass by extraction with water.

The reaction is normally carried out at a temperature above the freezingpoint of the system but preferably not above its boiling point. Stillmore preferably, the reaction is carried out at temperatures of fromabout C. to about 60C. The reaction is usually carried out atatmospheric pressure, but higher or lower pressures may be utilized ifequipment and other factors favor such higher or lower pressures. Thereaction may be carried out in an open vessel or under reflux.

Substituted l,l-dichlorosulfenamides of this invention are useful asbiocides. Exemplary of such biocidal uses for these products is thecontrol of nematodes, arachnids, arthropods and insects as well aseradication of noxious weeds. These compounds are particularly useful aspre-emergent and contact herbicides.

Pre-emergent and contact herbicidal compounds are useful in theselective killing of weeds in crops. In using the compounds of thepresent invention as preemergent and contact herbicides, the compoundscan be used alone or in combination with a material referred to in theart as an adjuvant in liquid or solid form. Herbicidal formulations areprepared by admixing the compound which is the active ingredient of theformulation with an adjuvant including diluents, extenders, carriers andconditioning agents to provide compositions in the form of finelydivided particulate solids, granules, pellets, solutions, dispersions oremulsions. Thus, the active ingredient can be used with an adjuvant suchas a finely divided particulate solid, a liquid of organic origin,water, a wetting agent, dispersing agent, an emulsifying agent or anysuitable combination of these. The herbicidal of formulations usuallycontain from about 0.01 percent to about 99 percent by weight of theactive ingredient. Application of these formulations to the soil orgrowth media can be carried out by simply admixing with the soil, byapplying to the surface of the soil and thereafter dragging or discinginto the soil to the desired depth, or by employing a liquid carrier toaccomplish the penetration and impregnation. The application of liquidand particulate solid herbicidal formulations to the surface of soil orto above ground portions of plants can be carried out by conventionalmethods, e.g., power clusters, boom and hand sprayers and spray dusters.The formulation can also be applied from airplanes as a dust or a spraybecause of their effectiveness at low dosages. In a further method, thedistribution of the active ingredients in soil can be carried out byadmixture with the water employed to irrigate the soil. In suchprocedures, the amount of water can be varied with the porosity andwater holding capacity of the soil to obtain the desired depth ofdistribution of the active ingredients.-

The exact amount of active ingredient to be employed is dependent uponthe response desired in the plant as well as such other factors as theplant species and stage of development thereof, the specific soil anddepth at which the active ingredients are distributed in the soil andthe amount of rainfall as well as the specific active ingredientemployed. In foliar treatment, the active ingredients are applied inamounts from about 1 to about 50 or more pounds per acre. Inapplications to soil for the control of the growth of germinant seeds,germinative seeds, emerging seedlings and established vegetation, theactive ingredients are applied in amounts from about 0.1 to about 25 ormore pounds per acre. It is believed that one skilled in the art canreadily determine from the teachings of this specification the generalprocedure for any application.

Manufacture of dichloromethyl sulfenyl chlorides, used as startingmaterials in the preparation of the compounds of the present invention,is taught in my prior US. Pat. application Ser. Nos. 139,976 and 139,978filed May 3, 1971, now US. Pat. Nos. 3,770,824 and 3,792,088,respectively and each entitled Substituted Alpha, Alpha-Dichloro-MethaneSulfenyl Chlorides and Their Manufacture.

Amines used in the preparation of the compounds of the present inventionare either known compounds or may be prepared by prior art methods fromknown compounds.

As illustrative of this invention, but not limitative thereof, is thefollowing:

EXAMPLE 1 To a suitable reaction vessel equipped with an agitator ischarged approximately 100 milliliters (ml.) of benzene, approximately5.6 grams (g.), about 0.02 moles, of dichloro(diisopropylcarbamoyl)mehtyl sulfenyl chloride and approximately 2.52 g., about 0.04 moles, ofpyrrolidine. A precipitate forms almost immediately. The mass is heatedwith stirring to about C. and maintained at about 70C. for about 1 hour(hr.). The mass is cooled to about room temperature, about 23C., and theprecipitate is removed by filtration. Thereafter the benzene is removedby distillation leaving an oily residue. The oil is dissolved in pentaneand, upon cooling in dry ice, a yellow solid crystallizes out of thesolution. The yellow solid is separated from the liquid by filtration,is found to have a melting point of about 50 to 53C. and is identifiedas 2,2-dichloro- N,N diisopropyl-2-( l-pyrrolidinylthio )acetamideCalculated for c,,H,,c1,N os= C, 46.00; H, 7.08 Found: C, 45.12, H, 7.13

EXAMPLE 2 Following the procedure of Example 1 except that, in place ofpyrrolidine, about 5.1 g. of octahydro-ll-lazonine is charged to thevessel and the resultant product is identified as2,2-dich1oro-N,N-diisopropyl-Z- (octahydrol l-l-azoninl -ylthio)acetamide a white solid with a melting point of about 116 to 119C.

Calculated for C H CI N OS: C, 52.0 Found: C, 52.2

EXAMPLE 3 Following the procedure of Example 1 except that, in

place of pyrrolidine, about 4 grams of 2,5-dimethyl pyrrolidine ischarged to the vessel and the resultant product is identified as2,2-dichloro-N,N-diisopropyl-Z- (2,5-dimethyll-pyrrolidinylthio)acetamide a white solid with a melting point of about50 to 52C.

Calculated for C H CEN OS: C, Found: C,

EXAMPLE 4 remaining oil, the mass is cooled in dry ice, andcrystallization is initiated by scratching the interior surface of thevessel below the liquid surface. Additional tan crystals are formed uponevaporation of the petroleum ether. The tan crystals are found to have amelting point of about 63 to 64C. and are identified as 2,2-dichloro-N-isopropyl-2-(octahydro-lH-azoninl-ylthio) acetanilideCH3-CH-Cli 3 Calculated for C H CI N OS: C, 56.

57; Found: C, 57.05

EXAMPLE 5 A suitable reaction vessel equipped with an agitator ischarged with about 200 ml. of diethyl ether and about 3.12 g. of2-(chlorothio)-2,2-dichloro-N- isopropylacetanilide is dissolved in theether, before about 2.14 g. of N-methylaniline is added. The mass isstirred for about one hour and the precipitate which forms is removed byfiltration. Any remaining ether is stripped from the liquid by vacuumdistillation, the remaining solid is then washed with petroleum etherand the washings retained. The solid is. identified as N- methylanilinehydrochloride. The retained washings are distilled to remove thepetroleum ether and the remaining oil is identified as2,2-dichloro-N-isopropyl-2- (N-mehtylanilinothio)acetanilide Calculatedfor c H cnNps; C, 56.4 H 5.26; N, 7.3] Found: C, 56.30; H, 5.15; N, 7.48

EXAMPLE 6 A suitable reaction vessel equipped with an agitator ischarged with about ml. of diethyl ether and approximately 3.l2 g., about0.01 moles, of 2- (chlorothio )-2 ,2-dichloro-N -isopropylacetanilide isdissolved in the ether before approximately 1.42 g., about 0.02 moles,of pyrrolidine is added. A precipitate forms immediately and, after themass is stirred for about 5 minutes, is removed by filtration. Theremaining liquid is distilled to remove the ether and the residual iscrystallized upon scratching. The crystals have a 5 melting point ofabout 77 to 79C. and are identified as2,2-dichloro-N-isopropyl-2-(l-pyrrolidinylthio) acetanilide Cll CHCll5.8 N 8.07 Found: C, 51.73; 8.07

EXAMPLE 7 separated by filtration, found to have a melting point ofabout 82 to 84C. and identified as 2-(diethylaminothio)-N-isopropyl-2,2,3 ,4'- tetrachloroacetanilide cn cncac H c1 NCCCl -SN 2 5 2% Calculated for C, H C1 N OS: C, 43.08; H, 4.82;N, 6.70 Found: C, 43.00; H, 4.84; N, 6.63

EXAMPLE 8 Following the procedure of Example 7 except that, in place ofdiethylamine, about 2 grams of di-2- propenylamine is added and theresidual oil is crystallized from petroleum ether rather than pentane,the resultant product, having a melting point of about 64 to 66C., isidentified as 2-(di-2-propenylaminothio)-N-isopropyl-2,2,3,4'-tetrachloroacetanilide Following the procedure ofExample 7 except that, in place of diethylamine, about 2.3 g. ofhexahydrol(2H)-azocine is added and the residual oil is dissolved in amixture of about percent by volume petroleum ether and about 10 percentby volume diethyl ether. Upon cooling in dry ice no precipitate appearsbut upon slow warming from about 70C. a precipitate comes out which isisolated by filtration, is found to have a melting point of about 52 to54C. and is identified as 2-( hexahydro- 1 (2H )-azocinylthio)-N-isopropyl- 2,2,3',4'-tetrachloroacetanilide Calculated for C,,.HCl.,N OS: C, 47.17;

Found: C, 47.0

EXAMPLE 10 To a suitable reaction vessel equipped with an agitator ischarged about ml. of benzene. Approximately 5.6 g. ofdich1oro(diisopropylcarbamoyl)methyl sulfenyl chloride is added anddissolved in the benzene. Approximately 1.7 g. ofl,l-dimethyl-2-propynylamine is added and a precipitate forms almostimmediately. The mass is stirred overnight at ambient room temperature,about 23C, and the precipitate is removed by filtration. The benzene isthen removed leaving a residual oil. The oil is dissolved in pentane andcooled in dry ice. Upon cooling a precipitate appears which is separatedfrom the liquid by filtration, dissolved in and recrystallized frompetroleum ether, and separated from the petroleum ether by filtration.The white solid product, with a melting point of about 81 to 83C. isidentified as 2,2-dichloro-N,N-diisopropyl-Z-[( l,l-dimethyl-2-propynyl)aminothio1acetamide CH CHCH O H CH I II I I l CH CHCl1 CH3Calculated for C H Cl N OS: C, 48 H, 6.82 Found: C, 48.04; H, 6.95

EXAMPLE 1 1 To a suitable reaction vessel equipped with an agitator ischarged approximately 100 ml. of benzene and approximately 2.92 g.,about 0.01 moles, of dichloro(phenylsulfonyl)methyl sulfenyl chloride.After the choride is dissolved in the benzene, approximately 2.54 g.,about 0.02 moles, of octahydro-l l-l-azonine is added to the solution.The reaction mass is stirred for about 1 hour and the hydrochloride saltprecipitate which forms is separated from the liquid by filtration.Solvent is removed by distillation leaving a residual solid. Theresidual solid is dissolved in petroleum ether and cooled in dry icewhereupon a precipitate forms. The precipitate which forms is separatedfrom the ether by filtration, found to have a melting point of about 88to 89C., and identified as a,oz-dichloro-a-(octamethyleneiminothio)methyl phenylsulfone A s-cc1 -swi 8 Calculatedfor C l-l Cl NO S C, 47.12; H, 5.54; N, 3

Found: C, 47.14; H, 5139; N, 3.

EXAMPLE 12 The procedure of Example 11 is followed except that, in placeof octahydro-lH-azonine, about 1.7 g. of 1,1-dimethyl-2-propynylamine isadded. A residual oil is obtained which upon recrystallization forms asolid with a melting point of about 81 to 83C. which is identified asa,a-dichloro-a-(3,3-dimethyl propargylaminothio)methyl phenylsulfone o Hcm Calculated for C, H, Cl NO- S C, 42.61: Found: C, 42.57;

EXAMPLE 13 To a suitable reaction vessel equipped with an agitator ischarged about 150 ml. of benzene and then ap- Examp le 10 dissolved inpetroleum ether and cooled in dry ice whereupon a precipitate forms. Theprecipitate is removed from the liquid by filtration and dissolved againin petroleum ether. Upon cooling in dry ice again a precipitate isformed which is removed by filtration. The white solid is found to havea melting point of about 56 to 58C. and identified as2,2-dichloro-2',6'-diethyl-N- methoxymethyl-2-( l-pyrrolidinylthio)acetanilide cu ocH cu -ca :\'ccc1. -s-n 2 2 Ch -CH Calculated for C HCl N O S: C, 53.33; H, 6.46 25 Found: C, 52.78; H, 6.51

EXAMPLES 14 through 31 The procedure of Example 1 is followed exceptthat,

in place of about 5.6 g. of dichloro(N,N-diisopropylcarbamoyl)methylsulfenyl chloride, an approximately equimolecular amount of the compoundof Column A is charged and the product of Column B is obtained:

s-cc1 s-c1 0 Qswcl -smdi 4 CF3 Y o C-CCl SN (Cl-12) 4 Continued CH3 CH Il cu cn cn cn O ccc1 -s-c1 ccc1 -s-2-: (CH2) 4 cu .':n cu cn I I 3 CH3 0O n n A EXAMPLES 32 through 37 1e procedure of Example 1 is followedexcept that, law of about 2.52 g. of pyrrolidine, an approximatelyequimolecular amount of the compound of Column A is charged and theproduct of Column B is ob- CH CHCH 3 -Continued Example A .B

36 c n oc n cn cncs o C2H40C2H5 (Cl-l c NH NC-CC12-S-N c cn 3 cn cncu 37cs cn oc4s cu cucn cu oc n l I cs N-l-l i-c-ccl -s-n CH3 cn cn o I CH3CH3 CH3 EXAMPLE 38 15 EXAMPLE 42 The procedure of Example 1 is followedexcept that, instead of removing the precipitate from the reaction mass,by filtration after cooling, about 200 ml. of water are added to themass upon cooling and the mass is stirred until the precipitate is nolonger visible. The mass then separates into an organic and an aqueousphase, the aqueous phase, which contains the dissolved precipitate, isremoved and the organic phase is then processed as in Example 1. Theproduct of Example 1 is obtained.

EXAMPLES 39 and 40 The procedure of Example 1 is followed except thatthe amount of pyrrolidine added is approximately 1.26 g., about 0.02moles, and, in addition, about 0.02 moles of the specified trialkylamine is added with the pyrrolidine. The product of Example 1 isobtained.

Example 39 Triethylamine.

Example 40 Tributylamine.

EXAMPLE 41 Contact herbicidal activity of representative substituteddichlorosulfenamides of this invention is determined by the followingprocedure:

The compound to be tested is applied in spray form to plants of a givenage of several grasses and broadleaf species. After the plants are thedesired age, each aluminum pan is sprayed with a given volume ofa 0.5percent concentration solution of the candidate chemical, correspondingto a rate of approximately 10 lbs. per acre. This solution is preparedfrom an aliquot of a 2 percent solution of the candidate compound inacetone, a known amount of cyclohexanone-emulsifying agent mix, andsufficient water to make up to volume. The emulsifying agent is amixture comprising 35 wt. percent butylamine dodecylbenzene sulfonateand 65 wt. percent of a tall oil-ethylene oxide condensate having about6 moles of ethylene oxide per mole of tall oil. The injuries to theplants are then observed approximately 14 days later and the results arerecorded.

Contact herbicidal activity of the compounds prepared in the designatedExamples is observed against the species as shown in Table I. X denotesthat herbicidal activity is observed. denotes that the species was nottested.

Pre-emergent herbicidal activity of representative substituteddichlorosulfenamides of this invention is determined by the followingprocedure:

A good grade of top soil is placed in aluminum pans and compacted to adepth of three-eighths to one-half inch from the top of the pan. Apre-determined number of seeds of each of several plant species areplaced on top of the soil in the pans. The seeds are covered with soiland the pans leveled. The herbicidal composition is applied by sprayingthe surface of the top layer of soil with a solution containing asufficient amount of active ingredient to obtain a rate of applicationof 5 lbs. per acre. The pans are then placed on a sand bench in thegreenhouse and watered from below as needed. The plants are observed atthe end of approximately 14 days and the results recorded.

Pre-emergent activity of the compounds prepared in the designatedExamples is observed against the species as shown in Table II. X denotesthat herbicidal activity is observed. denotes that the species was nottested.

TABLE II Compound of Example Number I 2 4 X XXX X While this inventionhas been described with respect to certain embodiments it is to beunderstood that it is not so limited and that variations andmodifications thereof abvious to those skilled in the art to which thisinvention appertains can be made without departing from the spirit orscope thereof.

What is claimed is:

1. A substituted dichlorosulfenamide of the formula x Z CCl 5 N.\\wherein X is phenyl, phenyl substituted by l to 3 halo, phenylsubstituted by 1 to 3 trihalomethyl, or phenyl substituted by l to 3lower alkyl, A is hydrogen, methyl alkenyl having from 3 to 5 carbonatoms, inclusive, branched alkynyl having from 4 to 5 carbon atoms,inclusive, lower alkyl, lower alkoxyalkyl, and B is methyl alkenylhaving from 3 to 5 carbon atoms, inclusive, branched alkynyl having from4 to 5 carbon atoms, inclusive, phenyl, phenyl inclusive.

5. A compound of claim 2 wherein A is hydrogen, lower alkyl, loweralkoxyalkyl, methyl alkenyl having from 3 to 5 carbon atoms, inclusive,or branched alkynyl having from 4 to 5 carbon atoms, inclusive, and B isphenyl, or phenyl substituted by l to 3 halo, trihalomethyl, or loweralkyl.

6. The compound of claim 4 wherein B is l,l-dimethyl-2-propynyl and X isphenyl.

1. A SUBSTITUTED DICHLOROSULFENAMIDE OF THE FORMULA
 2. A compound ofclaim 1, wherein X is phenyl.
 3. A compound of claim 2 wherein A and Bare each lower alkyl, lower alkoxyalkyl, methyl alkenyl having from 3 to5 carbon atoms, inclusive, or branched alkynyl having from 4 to 5 carbonatoms, inclusive.
 4. A compound of claim 2 wherein A is hydrogen, B isbranched alkynyl having from 4 to 5 carbon atoms, inclusive.
 5. Acompound of claim 2 wherein A is hydrogen, lower alkyl, loweralkoxyalkyl, methyl alkenyl having from 3 to 5 carbon atoms, inclusive,or branched alkynyl having from 4 to 5 carbon atoms, inclusive, and B isphenyl, or phenyl substituted by 1 to 3 halo, trihalomethyl, or loweralkyl.
 6. The compound of claim 4 wherein B is 1,1-dimethyl-2-propynyland X is phenyl.